Method and apparatus for sequence distributing and sequence processing in communication system

ABSTRACT

A sequence distributing and sequence processing method and apparatus in a communication system are provided. The sequence distributing method includes the following steps of: generating sequence groups including a number of sequences, the sequences in the sequence groups are determined according to the sequence time frequency resource occupation manner which is supported by the system; distributing the sequence groups to cells. The method avoids the phenomenon that signaling transmission is needed to distribute the sequences to the cells for different time frequency resource occupation manner, and saves in so far as possible the wireless network transmission resource occupied during the process of distributing the sequences through distributing the sequence groups comprising a number of sequences to the cells.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/413,105, filed on Mar. 27, 2009, which is a continuation ofInternational Application No. PCT/CN2007/070774 filed on Sep. 25, 2007,which claims priority to Chinese Patent Application No. 200610159666.7filed on Sep. 30, 2006, Chinese Patent Application No. 200610173364.5filed on Dec. 30, 2006, Chinese Patent Application No. 200710073057.4filed on Mar. 7, 2007, and Chinese Patent Application No. 200710111533.7filed on Jun. 19, 2007, all of which are hereby incorporated byreference in their entireties.

FIELD OF THE INVENTION

The present invention relates to communication technology, and inparticular, to a sequence allocating method, a sequence processingmethod and a sequence processing apparatus in a communication system.

BACKGROUND OF THE INVENTION

Constant amplitude zero auto-correlation (CAZAC) sequence has followingcharacteristics:

The module of the amplitude is a constant. For example, the module maybe normalized to 1. A zero period auto-correlation. Except for themaximum correlation value with respect to the sequence itself, thesequence has a correlation value of zero with respect to other cyclicshifts.

For a sequence with above characteristics, a sequence in the frequencydomain obtained through Fourier transformation is also a CAZAC sequence,i.e. the sequence in the frequency domain also has the characteristicsof constant amplitude and zero auto-correlation.

Due to the above characteristics of the CAZAC sequence, much attentionis gradually paid to the CAZAC sequence during the design of acommunication system. A signal bearing the CAZAC sequence is widelyemployed in the communication system. For example, in a Single CarrierFrequency Division Multiple Access (SC-FDMA) system, within one symboltime, the sequence is modulated on each sub-carrier for transmission.When the sequence of the transmitted signal is known at a receiver, thereceiver may perform channel estimation by use of the received signal.Because the CAZAC sequence has constant amplitude in the time domain,the waveform shows small peak-to-average ratio in the time domain, andis easy to be transmitted by the transmitter.

Meanwhile, because the transmitted signal has the same amplitude on eachsub-carrier in the frequency domain, the receiver may fairly estimatethe channel fading on each sub-carrier, and the estimation performancemay not be affected because of relatively small amplitude of the signalon a sub-carrier.

At present, the method for allocating the CAZAC sequence for cells is asfollows: the CAZAC sequence is allocated once with respect to eachoccupation mode of time-frequency resources of the sequence.Furthermore, when the occupation modes of the time-frequency resourcesof the CAZAC sequence to be allocated are the same in different cells,different CAZAC sequences having the same length and having smallinter-sequence correlation value are allocated to the different cells.Thus, the signal interference between different cells is less. Forexample, as shown in FIG. 1, the occupation modes of the time-frequencyresources of the sequence in cell A and cell B overlap each othertotally, then CAZAC sequences having the same length are allocated forcell A and cell B respectively, where the two CAZAC sequences have lowcorrelation, so that the signal interference between cell A and cell Bmay be avoided.

SUMMARY OF THE INVENTION

An embodiment of the present invention provides a method for allocatingsequences in a communication system. The method includes:

generating a sequence group comprising a plurality of sequences, whereinthe sequences in the sequence group are determined according tooccupation modes of time-frequency resources of the sequences supportedin the system;

wherein the sequences in the sequence group at least comprises one ofthe following:

constant amplitude zero auto-correlation, CAZAC, sequence, a fragment ofCAZAC sequence, and the sequence obtained through combining a CAZACsequence with a fragment of a CAZAC sequence;

wherein the CAZAC sequence is a Zadoff-Chu sequence;

wherein when the occupation modes of time-frequency resources of thesequences at least comprise: different sequences occupying thetime-frequency resources having different bandwidths, the generating asequence group comprising a plurality of sequences comprises: taking twosequences occupying the time-frequency resources having differentbandwidths as the sequences in the sequence group; wherein indexes r_(i)of the two sequences comply with r_(i)=b_(i)·k+δ_(i), i=1,2; wherein thesame k indicates the same sequence group, b_(i), δ_(i) are determined bythe time-frequency resources having different bandwidths occupied by auser, and i=1, 2 differentiates different time-frequency resources;

and

allocating the sequence group to a cell.

An embodiment of the present invention further provides a sequenceprocessing method in a communication system. The method includes:

determining information of the sequence group allocated to a cell;

determining sequence generation information from the information of thesequence group according to the occupation mode of time-frequencyresources of the sequence;

generating the sequence according to the sequence generationinformation; and

performing sequence processing on the sequence generated;

wherein the sequences in the sequence group at least comprises one ofthe following:

constant amplitude zero auto-correlation, CAZAC, sequence, a fragment ofCAZAC sequence, and the sequence obtained through combining a CAZACsequence with a fragment of a CAZAC sequence;

wherein the CAZAC sequence is a Zadoff-Chu sequence;

wherein when the occupation modes of time-frequency resources of thesequences at least comprise: different sequences occupying thetime-frequency resources having different bandwidths, two sequencesoccupying the time-frequency resources having different bandwidths aretaken as the sequences in the sequence group; wherein indexes r, of thetwo sequences comply with r_(i)=b_(i)·k+δ_(i), i=1,2; wherein the same kindicates the same sequence group, b_(i), δ_(i) are determined by thetime-frequency resources having different bandwidths occupied by a user,and i=1, 2 differentiates different time-frequency resources.

An embodiment of the present invention further provides a wirelesscommunication apparatus for signal processing. The apparatus includes:

a cell sequence determining unit, configured to determine information ofsequence group allocated to a cell;

a time-frequency resource sequence determining unit, configured todetermine the sequence generation information from the information ofsequence group according to the occupation mode of time-frequencyresources of the sequence;

a sequence generating unit, configured to generate the sequenceaccording to the sequence generation information; and

a processing unit, configured to perform sequence processing on thesequence generated;

wherein the sequences in the sequence group at least comprises one ofthe following:

constant amplitude zero auto-correlation, CAZAC, sequence, a fragment ofCAZAC sequence, and the sequence obtained through combining a CAZACsequence with a fragment of a CAZAC sequence;

wherein the CAZAC sequence is a Zadoff-Chu sequence;

wherein when the occupation modes of time-frequency resources of thesequences at least comprise: different sequences occupying thetime-frequency resources having different bandwidths, two sequencesoccupying the time-frequency resources having different bandwidths aretaken as the sequences in the sequence group; wherein indexes r_(i) ofthe two sequences comply with r_(i)=b_(i)·k+δ_(i), i=1,2 ; wherein thesame k indicates the same sequence group, b_(i), δ_(i) are determined bythe time-frequency resources having different bandwidths occupied by auser, and i=1, 2 differentiates different time-frequency resources.

In the technical solution provided by the embodiments of the presentinvention, a sequence group containing a plurality of sequences isallocated to a cell, so that the phenomenon that the allocation of thesequence for the cell needs to be implemented via signaling transmissionwith respect to different occupation modes of time-frequency resourcesis avoided, and the wireless network transfer resources occupied duringthe process of sequence allocation may be saved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing that the occupation modes oftime-frequency resources of the sequence in different cells overlaptotally each other in the prior art;

FIG. 2 is a first schematic diagram showing that the occupation modes oftime-frequency resources of the sequence in different cells overlappartially each other in the prior art;

FIG. 3 is a second schematic diagram showing that the occupation modesof time-frequency resources of the sequence in different cells overlaptotally each other in the prior art;

FIG. 4 is a schematic diagram showing the flow of a sequence allocatingand processing method according to an embodiment of the presentinvention;

FIG. 5 is a schematic diagram showing the correlation between a shortsequence and a fragment of a long sequence according to an embodiment ofthe present invention;

FIG. 6 is a schematic diagram showing the correlation between a sequencefragment and a sequence sample according to an embodiment of the presentinvention;

FIG. 7 is a schematic diagram showing the structure of a communicationsystem according to an embodiment of the present invention;

FIG. 8 is a schematic diagram showing the structure of an apparatus in acommunication system according to an embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The embodiments of the invention are described as follows in conjunctionwith the drawings.

During the process of implementing the present invention, the inventorfinds that there are at least following two problems in the prior art:

1. Large numbers of wireless network resources are occupied. In theexisting method for allocating the CAZAC sequence, when a CAZAC sequenceprocessing is to be performed, the allocation of CAZAC sequence for thecell needs to be implemented via signaling transmission with respect toeach occupation mode of time-frequency resources, and the signaling forallocation of CAZAC sequence for the cell occupies large numbers of thewireless network resources.

2. If it is not considered that when the occupation modes oftime-frequency resources of the CAZAC sequences in different cellspartially overlap each other, relatively strong signal interference mayexist between the cells. In the existing procedure of CAZAC sequenceallocation, when the occupation modes of time-frequency resources of theCAZAC sequences to be allocated in different cells are not totally thesame, it is considered that strong signal interference may not beproduced between the cells. Therefore, during the CAZAC sequenceallocation, the correlation between the CAZAC sequences corresponding todifferent occupation modes of time-frequency resources allocated todifferent cells is not considered. For example, as shown in FIG. 2 andFIG. 3, in the case that the occupation modes of time-frequencyresources of the sequences in cell A and cell B partially overlap eachother, when the correlation value of the CAZAC sequences allocated tocell A and cell B is relatively high, there is relatively strong signalinterference between cell A and cell B.

In the embodiments of the invention, a system allocates a sequence groupto a cell, where the sequences in each sequence group are divided intoseveral sub-groups. Each sub-group corresponds to an occupation mode oftime-frequency resources. The number of sub-group is the same as that ofthe occupation mode of time-frequency resources in the communicationsystem. The sequences in each sub-group are obtained by selecting from aset of candidate sequences corresponding to the sub-group. A user orchannel selects a sequence in the corresponding sequence sub-group fortransmitting or receiving according to the allocated sequence group andthe occupation mode of time-frequency resources of the employed specifictransmission signal. There may be one or more sequences in onesub-group.

FIG. 4 is a schematic diagram showing the flow of a sequence allocatingand processing method in the communication system according to anembodiment of the invention.

As shown in FIG. 4, in Step 401, the sequence group including aplurality of sequences is generated, and one or more sequence groupsincluding the plurality of sequences are allocated for a cell. Thesequences in the sequence group are determined according to theoccupation mode of time-frequency resources of the sequence supported bythe system. The occupation mode of time-frequency resources of thesequence is the mode of time-frequency resources bearing the sequence,i.e., the correspondence relation between the sequence and thetime-frequency resources. By allocating the sequence group including theplurality of sequences for the cell, the allocated sequence group may benotified through the identification information of the cell or theidentification information of the sequence group, so that the phenomenonthat the allocation of the sequence for the cell needs to be implementedvia signaling transmission with respect to different occupation modes oftime-frequency resources is avoided, and the wireless network transferresources occupied during sequence allocation is saved.

For different time-frequency resources that may be occupied by thesequences to be transmitted, the constitution method of the plurality ofsequences in the sequence group provided by the solution according tothe invention includes ensuring that these sequences have the followingcharacteristic:

When these sequences occupy the corresponding time-frequency resources,the correlation between these sequences are relatively high.

In other words, when occupying the corresponding time-frequencyresources, the sequences having relatively high correlation between eachother constitute a group.

When different groups are constituted according to the above principle,it can be ensured that the sequences in different groups have relativelysmall correlation between each other after the sequences occupy thecorresponding time-frequency resources.

Then the flow goes to Step 402. The function of allocating the sequencegroup for the cell includes allocating the sequence group for the useror channel in the cell.

When a user terminal needs to perform a sequence processing, such astransmitting the sequence, in Step 402, the user terminal determines thesequence group allocated to the present cell, determines the informationof the sequence to be transmitted in the sequence group of the presentcell according to the occupation mode of time-frequency resources of thesequence that needs to be transmitted, and then generates thecorresponding sequence according to the information of the sequence thatneeds to be transmitted. For example, the user terminal determines theidentification information of the sequence that needs to be transmitted,and generates the corresponding sequence according to the identificationinformation. In the present step, the user terminal may determine thesequence group allocated to the present cell according to the cellinformation such as cell ID information. Alternatively, the userterminal may determine the sequence group allocated to the present cellaccording to the ID information of the sequence group allocated to thepresent cell. Then the flow goes to Step 403. In Step 403, the userterminal uses the generated sequence for signal modulation, andtransmits the modulated signal.

When the network needs to perform sequence processing, such as receivingthe sequence, in Step 402, the network determines the sequence groupallocated to the corresponding cell, determines the information of thesequence to be received in the sequence group of the present cellaccording to the occupation mode of time-frequency resources of thesequence that needs to be received, and then generates the correspondingsequence according to the information of the sequence that needs to bereceived. For example, the network determines the identificationinformation of the sequence that needs to be received, and generates thecorresponding sequence according to the identification information. Inthe present step, the network may determine the sequence group allocatedto the cell according to the cell information such as cell IDinformation. Alternatively, the network may determine the sequence groupallocated to the present cell according to the ID information of thesequence group allocated to the present cell. Then the flow goes to Step403. In Step 403, the network uses the generated sequence for sequencereception. For example, the network uses the generated sequence and thereceived signal to perform correlation calculation.

In the description of the above embodiment, the cell may be allocatedwith one sequence group, or the cell may be allocated with a pluralityof sequence groups. The allocated sequence groups are specific to thecell, i.e. different cells may be allocated with different sequencegroups.

The sequences in a sequence group are determined according to theoccupation modes of time-frequency resources of the sequences. Thesequence group may be constituted according to the correlation betweenthe sequences occupied the corresponding time-frequency resources. Inother words, the sequences having relatively large correlation valuebetween each other may constitute into a sequence group. The sequenceshaving relatively large correlation value between each other refer to nsequences in the candidate sequences having the largest correlationvalues, where n is smaller than the total number of the candidatesequences. For example, the candidate sequences are arranged in turnfrom large to small with respect to the correlation value, the sequenceshaving the first largest correlation value, the second largestcorrelation value, . . . , the n-th largest correlation value are nsequences having the largest correlation value, where n may be 1. Withthe sequence group obtained in this way, it can be ensured that thecorrelation value between the sequences of different sequence groups isrelatively small. Thus, even in the case that the occupation modes oftime-frequency resources of the sequences in different cell overlappartially each other, it can be ensured that the signal interferencebetween the cells is relatively small.

The sequence in the sequence group in the embodiment of the inventionmay be CAZAC sequence. The CAZAC sequence may be Zadoff-Chu sequence, ormay be General chirp-like (GCL) sequence, etc.

The formula for generating the Zadoff-Chu sequence may be as shown inEquation (1):

a _(r,N)(n)=W _(N) ^(n(n+N mod2)/2+qn) , n=0, 1, . . . , N−1;   Equation(1)

where a_(r,N)(n) represents the sequence generated with index r, nrepresents the n-th element of the sequence, N represents the length ofthe sequence, W_(N)=exp(−j2πr/N), r and N are relatively prime numbers,and q is an arbitrary integer.

It can be known from Equation (1) that the length of the sequence may becontrolled by using parameter N, generating of different sequenceshaving the same length may be controlled by using index r, and q maycorrespond to the cyclic shift of the Zadoff-Chu sequence, or it may beconsidered that different q corresponds to different sequences.

In the embodiment of the invention, when the occupation mode oftime-frequency resources of the sequence is employed to determine thesequence in the sequence group, the sequence in the sequence group maybe determined according to the time-frequency resources of differentbandwidths corresponding to different sequences, may be determinedaccording to the time-frequency resources corresponding to differentsequences that have different sampling intervals in the frequency domainand have the same bandwidth after sampling, or may be determinedaccording to the positions of different time-frequency resource blockscorresponding to different sequences. Certainly, the sequence in thesequence group may also be determined according to other occupationmodes of time-frequency resources. For example, the sequence in thesequence group may be determined according to the time-frequencyresources that have different sampling intervals in the frequency domainand have different bandwidths after sampling. The embodiment of theinvention does not limit the specific form of the occupation mode oftime-frequency resources of the sequence.

Hereinafter, the specific implementing processes of the method forgenerating the sequence group, determining the sequences in the sequencegroup and allocating the sequence for the user/channel will beillustrated.

Embodiment I

In the case that different sequences correspond to the time-frequencyresources having different bandwidths, such as in the case as shown inFIG. 2, the method for generating the sequence group and determining thesequences in the sequence group may be as follows.

It is assumed that there are totally 150 sub-carriers available in thetime-frequency resources having a bandwidth of 5 MHz. There are twomodes included in the occupation modes of time-frequency resources ofthe sequence supported by the system: in one mode, the time-frequencyresources having the bandwidth of 5 MHz are divided into 4time-frequency resources each having a bandwidth of 1.25 MHz, then theoccupation mode of time-frequency resources of the CAZAC sequence is anoccupation mode of time-frequency resources having a bandwidth of 1.25MHz, i.e., the transmission bandwidth is 1.25 MHz; in the other mode,the occupation mode of time-frequency resources of the CAZAC sequence isan occupation mode of time-frequency resources having a bandwidth of 5MHz, i.e., the transmission bandwidth is 5 MHz.

The modulation signal transmitted by a cell may employ a fragment of theCAZAC sequence or a cyclic extension of the CAZAC sequence. Generallyspeaking, various combinations of various sequence fragments may beemployed. Especially when the number of the sub-carriers carrying theCAZAC sequence in the cell is just not a prime number, or when the cellin a cellular system needs to use a longer CAZAC sequence so as toobtain more CAZAC sequences that are different, the sequence to betransmitted may be formed by using the sequence fragment or fragmentcombination.

For a transmission bandwidth of 5 MHz, the length of the CAZAC sequencecorresponding to the available 150 sub-carriers may be a prime numberN=151, and the length of the CAZAC sequence may be intercepted as 150.

For a transmission bandwidth of 1.25 MHz, the number of availablesub-carriers may be a prime number 37, then the length of the CAZACsequence corresponding to the available 37 sub-carriers in thetransmission bandwidth of 1.25 MHz may be the prime number N=37.

In the case that the occupation mode of time-frequency resources of thesequence includes two modes, i.e. a transmission bandwidth of 1.25 MHzand a transmission bandwidth of 5 MHz, and one sequence group includestwo Zadoff-Chu sequences, the process of generating the sequence groupand the sequences in the sequence group by using the Zadoff-Chu sequenceis as follows:

A Zadoff-Chu sequence having a length of 37, the sequence index isr=b₁·k, where b₁=1, k=1, 2, 3, . . . , 34, 35, 36. A Zadoff-Chu sequencehaving a length of 150, i.e., a fragment of a Zadoff-Chu sequence havinga length of 151, the sequence index is r=b₂·k, where b₂=4, k=1, 2, 3, .. . , 150. The Zadoff-Chu sequence having the length of 37 is a shortsequence with respect to the Zadoff-Chu sequence having the length of150, and the Zadoff-Chu sequence having the length of 150 is a longsequence with respect to the Zadoff-Chu sequence having the length of37.

The long sequence may include 150 Zadoff-Chu sequences, and the shortsequence may include 36 Zadoff-Chu sequences. Two Zadoff-Chu sequenceshaving the same k constitute a sequence group, and the other twoZadoff-Chu sequences having different k constitute a different sequencegroup. Therefore, when it is not allowed to repeatedly use the shortsequence, 36 sequence groups may be generated by performing setintersection of the above long sequence and short sequence. When it isallowed to repeatedly use the short sequence, 150 sequence groups may begenerated. During the practical calculation, a module calculation may beperformed for r with respect to N, where N is the length of theZadoff-Chu sequence. When k=±37, ±74, r=(k·b₁)mod37=0, whereas when r=0,it does not correspond to a Zadoff-Chu sequence. Therefore, k=±37, ±74may be discarded. Thus, 146 sequence groups may be generated.

Generally, when different sequences occupy the time-frequency resourcesof different bandwidths, i.e., when the occupation modes oftime-frequency resources of different sequences are different, theindexes of the long sequence and short sequence corresponding to thetime-frequency resources of two different bandwidths should satisfy thefollowing relation: r_(i)=b_(i)·k+δ_(i), i=1,2; where the same kindicates the same sequence group, b_(i), δ_(i) is determined by thetime-frequency resources occupied by the sequence, and a special case isthat δ_(i)=0, i=1, 2 is used to differentiate different time-frequencyresources. b₁,b₂ are determined by the proportion of the time-frequencyresources occupied by the sequences. Specifically, b₁, b₂ are determinedby the number of the sub-carrier occupied by the two sequences. There isa plurality of options available. A preferred option is to determine b₁,b₂ according to the equation b₁·N₂−b₂·N₁=1. In other words, for anarbitrary sequence, b_(m),b_(i) are first determined to obtainN₁·b_(m)·b₁=1, then for any r₁=k·b₁, there is r_(m)=k·b_(m),−N₁/2<k<N₁/2. Thus, the correspondence relation between the sequences ina group is given. When a plurality of sequences in a sub-group m is tobe determined, the relation is r=k·b_(m)±δ, where δ is a small integer.

Specifically, it is assumed that there are 3 sub-groups totally, whichare Zadoff-Chu sequences having a length of 11, 23 and 37 respectivelyand correspond to three resource occupation modes. When N₁=11, thenthere are totally 10 sequence groups. The following table may beobtained:

N₁ = 11 N₂ = 23 N₃ = 37 Group index k, r₁ r₂ r₃ 1 2 3 2 4 7 3 6 10 4 813 5 10 17 6 13 20 7 15 24 8 17 27 9 19 30 10 21 34

After practical calculation, it is proved that the correlation betweenthe sequences in the table is fairly high indeed.

For a bandwidth of 1.25 MHz, the number of sub-carriers occupied by thesequence is N₁=37. For a bandwidth of 5 MHz, the number of sub-carriersoccupied by the sequence that is not intercepted is N₂=151. During thedetermination of b₁ and b₂, b₁ and b₂ may be determined according to avalue close to 37/151, and be determined according to the equationb₁·N₂−b₂·N₁=1, for example, b₁=25 and b₂=102; and it may be selectedthat k=−L, −L+1, . . . , −1, 1, 2, . . . , L−1, L,L=(N₁−1)/2−(37−1)/2=18, δ₁=0, δ₂=±1, ±2, . . . Alternatively, it may beselected that δ₁=δ₂=0, k=−L, −L+1, . . . , −1, 1, 2, . . . , L−1, L,L=(N₂−1)/2=(151−1)/2=75, and k≠m·37, m is an integer m=0, ±1, ±2, . . .. The sequences having a length of 37 included in k and k+m·37 sequencegroups are the same, whereas the sequences having a length of 151included therein is not the same.

According to the embodiment of the invention, 36 sequence groups may begenerated, and there may be one or more sequences having a length of 151in each sequence group. No matter whether 36 sequence groups or 146sequence groups are generated, different sequence group may be allocatedto different cell after the sequence groups are generated.

Specifically, when the sequence in a sequence group such as a fragmentof the CAZAC sequence or a cyclic extension of the CAZAC sequence iscarried in a domain such as frequency domain, cyclic shift processingmay be performed in the other domain for the sequence in the sequencegroup. The new sequence generated after cyclic shifting may be used asthe sequence in this sequence group, or may be used as the sequence inthe other sequence groups. For example, a fragment of the CAZAC sequencein a sequence group is carried in the frequency domain, then a discreteinverse Fourier transform may be performed on this fragment of the CAZACsequence in the sequence group, and a time waveform is obtained, i.e. asequence in the time domain is obtained. Then the sequence in the timedomain is cyclic shifted to generate one or more sequences in the timedomain, and the sequences in the time domain are used as the sequencesin this sequence group or other sequence groups.

When the sequences generated by cyclic shifting a sequence are allocatedto different sequence groups, it may be considered that the sequencesgenerated after cyclic shifting are a plurality of sequences. Thus, whena sequence in a sequence group is cyclic shifted differently, differentsequence groups may be obtained.

The aforementioned cyclic shifting means that a posterior segment of thesequence is copied to the anterior part of the sequence. For example,when the fragment of the original CAZAC sequence is transformed to thetime domain and forms a time waveform having a length of s, i.e., asequence a₀, a₁, . . . , a_(s−1), then after the cyclic shift, it may betransformed to a_(p+1), a_(p+2), . . . , a_(s−1), . . . , a₀, a₁, . . ., a_(p), where p may be an integer selected from 0, 1, 2, . . . , s−1.

In the case that the positions of the time-frequency resource blockscorresponding to different sequences are different, the method forconstituting the sequence group and determining the sequence in thesequence group may be as follows.

In the embodiment of the invention, the positions of the above 4time-frequency resource blocks having transmission bandwidths of 1.25MHz are different. In other words, there are 4 different occupationmodes of time-frequency resources. For a transmission bandwidth of 1.25MHz, because the number of available sub-carriers may be the primenumber 37, the length of the CAZAC sequences corresponding to the 37sub-carriers available in the transmission bandwidth of 1.25 MHz may bethe prime number N=37. So 36 sequence groups may be generated. Thespecific process of constituting the 36 sequence groups is as describedin the above first embodiment. Each sequence group may include a CAZACsequence. If the CAZAC sequence in the sequence group is used as a basesequence, and then cyclic shifting is performed on the base sequence andthe sequences after cyclic shifting are still taken as the sequences inthe sequence group where the corresponding base sequence exists, aplurality of sequences may be included in a sequence group. For example,4 different cyclic shifts are performed on a base sequence, and 4sequences are obtained after the cyclic shifts. The 4 sequences aftercyclic shifting and the base sequence are used as the sequences in thesame sequence group. Thus, a sequence group may include 5 sequences.

In the embodiment of the invention, it is not excluded the case that thesame sequence is used for the above 4 time-frequency resource blocks oftransmission bandwidths of 1.25 MHz with different position, i.e., thecase that during the determination of the sequence in the sequencegroup, the different positions of the time-frequency resource blocks ofthe sequence are not considered. At this time, there may be 2 CAZACsequences in a sequence group.

In the case that different sequences correspond to the time-frequencyresources that have different sampling intervals and have the samebandwidth after sampling, such as in the case as shown in FIG. 3, themethod for constituting the sequence group and determining the sequencesin the sequence group may be as follows.

In the case shown in FIG. 3, the occupation modes of time-frequencyresources of the sequence supported by the system include the followingtwo modes:

Mode I: the time-frequency resources having a bandwidth of 10 MHz aredivided into two time-frequency resources having a bandwidth of 5 MHz.

Mode II: Through sampling interval 2, time-frequency resources havingthe bandwidth of 5 MHz are obtained through sampling from thetime-frequency resources having the bandwidth of 10 MHz.

Hereinafter, the Zadoff-Chu sequence is taken as an example toillustrate the Zadoff-Chu sequence generated in the same sequence group.

It is assumed that N=151, r=k, a sequence having a length of 150 isobtained through interception, and a fragment of the Zadoff-Chu sequencecorresponding to the bandwidth of 5 MHz is generated.

It is assumed that N=151, r=4·k, a sequence having a length of 150 isobtained through interception, and a fragment of the Zadoff-Chu sequencecorresponding to the bandwidth of 10 MHz having the sampling interval of2 is generated.

The aforementioned k is a natural number between 1 to 150. In otherwords, for the transmission bandwidth of 5 MHz and the bandwidth of 10MHz having sampling interval of 2, 150 sequence groups may be generated.The indexes of the Zadoff-Chu sequences corresponding to thetime-frequency resource having different sampling intervals in the samesequence group are directly proportional to the square of the samplingintervals.

In the present embodiment, different k corresponds to the differentsequence groups. There may be two CAZAC sequences in a sequence group,or more CAZAC sequences may be generated with the two CAZAC sequencesthrough cyclic shifting. When k is the same, the sequences obtainedthrough cyclic shifting may be regarded as the sequences in the sequencegroup having the value k. The CAZAC sequences obtained after cyclicshifting may be in the same sequence group as that of the base sequence.Alternatively, the CAZAC sequences obtained after cyclic shifting may bein the different sequence groups from that of the base sequence.

Generally, according to the CAZAC sequence theory, for a CAZAC sequencea_(i), i=0, . . . , M−1 having a length of M, if the sampling intervalis s, and M and s are relatively prime, then a_((si)mod M), i=0,1, . . .,M−1 is a CAZAC sequence. For the sampling intervals s₁ and s₂, the twosequences a_((s) ₁ _(i)mod M), i=0,1, . . . ,M−1 and a_((s) _(i)_(i)mod M), i=0,1, . . . , M−1 are in the same sequence group andcorrespond to different sampling intervals of the time-frequencyresources respectively. The above Zadoff-Chu sequence is only oneexample.

At a certain time point, there may be two or more occupation modes oftime-frequency resources of the sequence supported by the system. Forexample, the occupation modes of time-frequency resources of thesequence may be, as shown in FIG. 2 and FIG. 3, the sub-carriersoccupying the bandwidth of 1.25 MHz, the sub-carriers occupying thebandwidth of 5 MHz, and the sub-carriers obtained having the bandwidthof 10 MHz and the sampling interval of 2 respectively,. At this time,when the sequence group is allocated to each cell, the value of theindex r of the sequence is as follows:

The indexes r_(i) and r_(j) corresponding to the different occupationmodes of time-frequency resources satisfy the relation

${\frac{r_{i}/g_{i}^{2}}{r_{j}/g_{j}^{2}} = \frac{b_{i}}{b_{j}}},$

where g_(i) and g_(j) represent that in the two resource occupationmodes, every g_(i) sub-carriers and g_(j) sub-carriers in the frequencydomain occupy a sub-carrier, and b_(i)/b_(j) represents a valuedetermined by the ratio of the actually occupied bandwidths in the tworesource occupation modes. Generally, b_(i)/b_(j) may specifically be avalue determined by the ratio of the numbers of sub-carriers carryingthe sequences.

In the mode of the occupied sub-carriers covering the bandwidth of 1.25MHz, N=37, then r₁=a₁·k, a₁=1, where the possible maximum k is 36. Incomparison with the other two resource occupation modes, in this mode,when a selection of a_(m), m=2, 3 is performed under the condition that

$\frac{r_{i}/g_{i}^{2}}{r_{j}/g_{j}^{2}} = \frac{b_{i}}{b_{j}}$

is satisfied, it may selecte that b₁=36, b₂=150, b₃=150, then thefollowing may be obtained: it needs to set r₂=a₂·k, a₂=4 for the cellwith occupied sub-carriers covering the bandwidth of 5 MHz, where themaximum k is 150. In comparison with the mode in which the onesub-carrier is occupied every two sub-carriers and these sub-carrierscover the bandwidth of 10 MHz, it is required that r₃=a₃·k, a₃=16, wherethe maximum k is 150. However, in each case, there are only 36 values ofr/N finally obtained that are not repeated. Therefore, when it should besatisfied that the interference is relatively small in these threecases, there are only 36 sequence groups available for allocation.Generally, the number of the sequence groups available for allocation isrelevant to the number of the sequences obtained from the shortestsequence.

Through simulation, it is proved that when the time-frequency resourcescorresponding to the sequences in different sequence groups designedaccording to the embodiment of the invention are partially overlappedwith each other, when the sequences are modulated in the correspondingtime-frequency resources, the correlation between the modulatedsequences is relatively small, and the correlation between the sequencesin the same sequence group may be relatively large. Therefore, for theplanning of the cellular system, when different sequence groups areallocated to the different cells, it may be ensured that the correlationbetween the sequences of different cells is small, and the signalinterference between the cells is small.

For one certain cell, one or more sequence groups may be allocated tothis cell according to the embodiment of the invention. The number ofthe sequence group allocated to the cell may be determined according tothe actual situation of the network.

FIG. 5 shows the correlation between the sequences of two sequencegroups. The (37, 1), (37, 2) etc. in FIG. 5 represent (N, r), whichindicate the r-th sequence in the sequence having a length of N. It canbe seen from FIG. 5 that for the sequences with N=37, the values ofauto-correlation (except for the auto-correlation value of 37 in thezero shift position, the auto-correlation value is 0 in other shiftpositions) and the cross-correlation (the cross-correlation value is√{square root over (37)} in any shift positions) are very small. Whereasthe correlation between the fragment of the sequence with N=37 and thefragment of the sequence with N=151 is relevant to the value of r thatdetermines the sequence. It can be seen that there is a relatively highcross-correlation value between the sequence with N=37, r=1 and thesequence with N=151, r=4, and the largest cross-correlation value isabout 28. These two sequences belong to the same sequence group. Whereasthere is a relatively small cross-correlation value between the sequencewith N=37, r=1 and the sequence with N=151, r=2, and the largestcross-correlation value is about 11. These two sequences belong todifferent sequence groups.

Similarly, FIG. 6 also shows the correlation between the sequences oftwo sequence groups. The (151, 1), (151, 2) etc. in FIG. 6 represent (N,r), which indicate the r-th sequence in the sequence having a length ofN. It can be seen from FIG. 6 that for the sequences with N=151, thevalues of auto-correlation (except for the auto-correlation value of 151in the zero shift position, the auto-correlation value is 0 in othershift positions) and the cross-correlation (the cross-correlation valueis √{square root over (151)} in any shift positions) are very small.Whereas the correlation between the fragment having a length of 75 inthe sequence with N=151 and the fragment combined after sampling isrelevant to the value of r that determines the sequence. It can be seenthat there is a relatively high cross-correlation value between thesequence with N=151, r=1 and the sequence with N=151, r=4, and thecross-correlation peak value about 50 appears at the two shiftpositions. Whereas there is a relatively small cross-correlation valuebetween the sequence with N=151, r=1 and the sequence with N=151, r=2,and the cross-correlation values are smaller than √{square root over(151)} in all the shift positions, which proves that the correlationbetween the sequences of different sequence groups is relatively small.

Embodiment II

When there are a plurality of transmission signals having differentbandwidths in the system, i.e., when the occupation modes oftime-frequency resources of the sequences supported in the system are aplurality of different bandwidths, two sequences in a sequence group maybe constituted with the following method.

When an occupation mode of time-frequency resources is occupation of Nsub-carriers, and still a further occupation modes of time-frequencyresources is occupation of M sub-carriers, then a CAZAC sequencec_(i)=a_(i mod M)·b_(i mod N), i=0,1, . . . ,MN−1 having a length of M×Nmay be constituted according to a₀, a₁, . . . , a_(M−1) having a lengthof M, i.e., the sequence a_(i), and b₀, b₁, . . . , b_(N−1) having alength of N, i.e., the sequence b_(i), where the sequences b_(i) andc_(i) belong to the same sequence group.

Then, the occupation mode of time-frequency resources corresponding tothe sequence b_(i) is occupation of N sub-carriers, and the occupationmode of time-frequency resources corresponding to the sequence c, isoccupation of M×N sub-carriers. When M and N are relatively prime, thesequence constructed according to the above method still satisfies theCAZAC characteristics.

For example, the above embodiment may be employed in the applicationscenario as shown in FIG. 2: The time-frequency resources of thebandwidth of 1.25 MHz in a cell correspond to Zadoff-Chu sequence b,having a length of 37, whereas the Zadoff-Chu sequence corresponding tothe time-frequency resources in another cell is Zadoff-Chu sequencehaving a length of 148 which is constructed with a sequence b_(i) havinga length of 37 and a Zadoff-Chu sequence a_(i) having a length of 4. Inthe practical application, in order to match the number of sub-carriers,some interception or supplement to the sequence is necessary. If bothcells use the sequences corresponding to the same b_(i), i.e., use thesequences in the same sequence group, the correlation value between thesequences are relatively large. If both cells use the sequencescorresponding to different b_(i), i.e., use the sequences in differentsequence groups, the correlation value between the sequences arerelatively small.

For the Zadoff-Chu sequence, it can be proved that if M and N arerelatively prime, the sequence obtained with the two Zadoff-Chusequences having lengths of M and N respectively through the aboveoperation is a Zadoff-Chu sequence having a length of MN. The proof isas follows:

$a_{m} = {\exp \left\lbrack \frac{{- 2}\pi \; r_{1}{j \cdot \left( {{m\left( {m + {M\; {mod}\; 2}} \right)}/2} \right)}}{M} \right\rbrack}$$b_{n} = {\exp \left\lbrack \frac{{- 2}\pi \; r_{2}{j \cdot \left( {{n\left( {n + {N\; {mod}\; 2}} \right)}/2} \right)}}{N} \right\rbrack}$$\begin{matrix}{c_{i} = {a_{i\; {mod}\; M} \cdot b_{i\; {mod}\; N}}} \\{= {\exp \left\lbrack \frac{{- 2}\pi \; {j \cdot \left\{ {{r_{1}{{m\left( {m + {M\; {mod}\; 2}} \right)}/2}} + {r_{2}{{n\left( {n + {N\; {mod}\; 2}} \right)}/2}}} \right\}}}{MN} \right\rbrack}} \\{= {\exp \left\lbrack \frac{{- 2}\pi \; {j \cdot \left\{ {{{Nr}_{1}{{\left( { + {M\; {mod}\; 2}} \right)}/2}} + {{Mr}_{2}{{\left( { + {N\; {mod}\; 2}} \right)}/2}}} \right\}}}{MN} \right\rbrack}} \\{= {\exp \left\lbrack \frac{{- 2}\pi \; {j \cdot \left\{ {{{Nr}_{1}{{\left( { + {M\; {mod}\; 2}} \right)}/2}} + {{Mr}_{2}{{\left( { + {N\; {mod}\; 2}} \right)}/2}}} \right\}}}{MN} \right\rbrack}} \\{= {\exp \left\lbrack \frac{{- 2}\pi \; {j \cdot \left\{ {\left( {{Nr}_{1} + {Mr}_{2}} \right){{\left( { + {{MN}\; {mod}\; 2}} \right)}/2}} \right\}}}{MN} \right\rbrack}}\end{matrix}$

The above equations are true when M and N are both odd numbers.

When there is one odd number and one even number in M and N, and thedifference is only one cyclic shift, then the above equations are alsotrue. The proof is as follows, where it is assumed that M is an oddnumber and N is an even number.

$\begin{matrix}{c_{i} = {\exp \left\lbrack \frac{{- 2}\pi \; {j \cdot \left\{ {{{Nr}_{1}{{\left( { + {M\; {mod}\; 2}} \right)}/2}} + {{Mr}_{2}{{\left( { + {N\; {mod}\; 2}} \right)}/2}}} \right\}}}{MN} \right\rbrack}} \\{= {\exp \left\lbrack \frac{{- 2}\pi \; {j \cdot \left\{ {{{Nr}_{1}{\left( { + 1} \right)}{\left( {M + 1} \right)/2}} + {{Mr}_{2}{^{2}/2}}} \right\}}}{MN} \right\rbrack}} \\{= {\exp \left\lbrack \frac{{- 2}\pi \; {j \cdot \left\{ \left( {{{{Nr}_{1}\left( {M + 1} \right)}{^{2}/2}} + {{{Nr}_{1}\left( {M + 1} \right)}{/2}} + {{Mr}_{2}{^{2}/2}}} \right\} \right.}}{MN} \right\rbrack}^{\circ}} \\{= {\exp \left\lbrack {\frac{\left. {{- 2}\pi \; {j \cdot {\left\{ {\left( {{{Nr}_{1}\left( {M + 1} \right)} + {Mr}_{2}} \right)^{2}} \right)/2}}} \right\}}{MN} + {{\frac{2\pi \; j}{MN} \cdot {{Nr}_{1}\left( {N + 1} \right)}}{/2}}} \right\rbrack}}\end{matrix}$

Because r₁ and M are relatively prime, and r₂ and N are relativelyprime, so Nr₁+Mr₂ and M×N are relatively prime. Therefore, this sequenceis a Zadoff-Chu sequence.

Generally, for a Zadoff-Chu sequence having a length of M, and

${M = {\prod\limits_{i}^{\;}\; {p_{i}}^{k_{1}}}},$

p_(i) is different prime numbers, then this sequence is obtained throughmultiplication of several Zadoff-Chu sequences having a length of p_(i)^(k) ^(i) .

The above method may be summarized as follows: when there are threeoccupation modes of time-frequency resources, where one occupation modeof time-frequency resources corresponds to a short sequence a, oneoccupation mode of time-frequency resources corresponds to a shortsequence b, and the last occupation mode of time-frequency resourcescorresponds to a long sequence c, and the long sequence c is obtainedthrough the multiplication of the short sequence a and the shortsequence b, then the following method may be used during thedetermination of the sequence in the sequence group:

The long sequence c and the short sequence b are used as the sequencesin the same sequence group, and the occupation mode of time-frequencyresources of the long sequence c is different from that of the shortsequence b.

Certainly, the long sequence c and the short sequence a may also be usedas the sequences in the same sequence group, and the occupation mode oftime-frequency resources of the long sequence c is different from thatof the short sequence a.

Embodiment III

In the embodiment of the invention, during the allocation of one or moresequence groups to the cell, a random allocation mode or static planningmode may be used to allocate the sequence groups to the cell. When thestatic planning mode is used for allocation of sequences to the cell,the sequence group allocated to the cell is fixed one or more sequencesthat does/do not change with time.

The implementing process of allocating the sequence group to the cell ina dynamic allocation mode is illustrated as follows.

For a system covering bandwidth of 5 MHz, the frequency band having thebandwidth of 5 MHz may be uniformly divided into 25 basic units, and thescheduling bandwidth of the signal obtained with the sequence modulationmay be 1 basic unit, 2 basic units, . . . , or 25 basic units. Thus,corresponding to the combination of the basic units of these schedulablebandwidths, the sequences having 25 different lengths are required inthe system. When l₁,l₂, . . . , l₂₅ are used to represent the respectivelengths of the sequences having 25 different lengths, and the number ofthe sequences under each length l_(i) is represented with N_(i), thesequences under different lengths l_(i) may be numbered as r_(i,0),r_(i,1), . . . , r_(i,N) _(i−1) . A sequence group needs to include 25sequences, and the 25 sequences are represented as {r_(i,k mod N) _(i)|i=1,2, . . . ,25}, where k is the index of the sequence group, mod isthe module operation, k mod N_(i) determines the index r_(i,)* of thesequence in the sub-group i of the sequence group, where *=k mod N_(i).

In the embodiment of the invention, a pseudo random mode specific to thecell may be used to determine the sequence group allocated to the cell.For example, the present pseudo random number may be generated accordingto the information such as the number of the time slot where the presentsequence is located and the user ID, the pseudo random numbercorresponds to the index k of the sequence group. Then the length of thesequence, i.e., l_(i), is determined according to the width of thefrequency band occupied by the sequence, and the index of the sequenceunder this length in the selected sequence group numbered k is obtainedthrough r_(i,k mod N) _(i) , where mod is the module operation. In otherwords, the sequence group allocated to the cell may be achieved in themanner of module operation. The user terminal/network may use thesequence in the sequence group for signal processing, such as sequencetransmission, sequence signal reception, etc.

The pseudo random number may be generated with a shift register. Thepseudo random number sequence may be an m sequence or Gold sequence etc.in the common binary field or GF(q). Different cells may use differentinitial states of the shift register, or use the sequences that aredifferently shifted, to generate the pseudo random number sequences. Thek states (a₁, a₂, . . . , a_(k)) of the shift register correspond to theindex of the sequence group. Each time when the shift register turns,i.e., each time when the shift operation is performed, the state of theshift register is changed, so that a new state is generated. This newstate may correspond to the index of the sequence group used at the nexttime point.

In the embodiment of the present invention, cell group specificpseudo-random mode may be used for allocation of the sequence group. Forexample, three cells under a Node B may be regarded as one cell group,and the three cells in the cell group may use the same pseudo randomnumber sequence to determine the allocated sequence group. Differentcells may obtain the sequences that need to be processed, such as theorthogonalized signals to be transmitted, by differently shifting theselected sequences in the time domain. Alternatively, different cellsmay select a sequence from the plurality of different sequences in asequence group that correspond to the same occupation mode oftime-frequency resources and have small correlation, so as to obtain thesequences that need to be processed.

When the to the cell group specific pseudo random mode is used for theallocation of the sequence group, different cell groups may usedifferent pseudo random number sequences. For example, different cellgroups of the different Node Bs may use different pseudo random numbersequences.

When a plurality of sequences in the sequence group corresponds to anoccupation mode of time-frequency resources, the random mode may be usedto allocate the sequence to the user. For example, the occupation mode iof time-frequency resources corresponds to n sequences in the sequencegroup, and these n sequences are numbered with 0, 1, 2, . . . , n−1according to an order of the index r from small to large or according toother specific order. During the processing of the sequences, thesequence corresponding to the occupation mode i of time-frequencyresources is determined according to the index obtained through themodule operation (X mod n), where X is a random number. The randomnumber X may change with the change of the time slot or sub-frameoccupied by the sequence. The random number X here may be a randomnumber sequence. The sequence corresponding to the occupation mode oftime-frequency resources may be a base sequence and/or a sequencegenerated through different cyclic shifts. Equivalently, in theembodiment of the invention, the sequence group may be divided into aplurality of sub-groups through the method of module operation, andthese sequence sub-groups may be selected and allocated in the pseudorandom manner.

In the embodiment of the invention, the process of constitution andallocation of the sequence group may be performed with respect to someoccupation modes of time-frequency resources of the sequences in thesystem, i.e., the constitution process of the sequence group may not beperformed for all the occupation modes of time-frequency resources ofthe sequences in the system. For example, according to the length of thesequence, the occupation modes of time-frequency resources of thesequences may be classified into several classes, the set of theoccupation modes of time-frequency resources of the sequences in eachclass corresponds to the sequences having lengths within a certainrange. The above processing of generation and allocation of the sequencegroup may be performed for the sequences corresponding to the set ineach class.

For the sequence groups corresponding to the set of different occupationmodes of time-frequency resources of the sequences, the dynamic orstatic allocation mode may be used respectively to allocate differentsequence groups to the cell. For example, when the wireless resourcesoccupied by the sequence are relatively few, the dynamic allocation modemay be used to allocate the sequence groups to the cell. Because at thistime, the length of the sequence is relatively small, the index of thesequence group is relatively small, the requirements of using thesequences by the cell can be satisfied when the dynamic allocation modeis used to allocate the sequence groups to the cell. The implementationprocess of allocating the sequence groups to the cell in the dynamicallocation mode is as follows: in the embodiment where the Zadoff-Chusequence is taken as an example, one of pseudo random modes is used;during the transmission of the signal modulated with the sequence, anindex of the sequence group is selected randomly, and then one of themodes in the above description is used to calculate the sequence withthe sequence index r which belongs to the sub-group of the correspondinglength in the same sequence group.

In another example, when the sequence occupies many wireless resources,the static allocation mode is used to allocate the sequence groups tothe cell. For example, in the embodiment where the Zadoff-Chu sequenceis used as an example, if the number N of the sequence groups cansatisfy the requirements of the cell to use the sequences, the Nsequence groups are allocated to different cells for using. At thistime, the sequence groups allocated to the cell does not need to changeas the time changes, and the requirements of averaging the signalinterferences between the cells can also be satisfied.

Preferably, the wireless resources occupied by the sequence may beclassified into two classes in the system, and sequence groups areconstituted respectively. In one class, the sequence occupies manywireless resources, and the static allocation mode may be used toallocate sequence groups to the cell for this class. In the other class,the sequence occupies few wireless resources, and the dynamic pseudorandom mode may be used to allocate sequence groups to the cell for thisclass. For example, when the time-frequency resources occupied by thesequence exceed 144 sub-carriers, the length of this sequence is largerthan or equal to 144. For the case that the time-frequency resourcesoccupied by the sequence exceed 144 sub-carriers, the static allocationmode may be used to allocate sequence groups to the cell. When thetime-frequency resources occupied by the sequence are less than 144sub-carriers, the length of this sequence is smaller than 144. For thecase that the time-frequency resources occupied by the sequence are lessthan 144 sub-carriers, the dynamic pseudo random mode may be used toallocate sequence groups to the cell.

In the above embodiment, the processes of generating the sequence groupand constituting the sequence in the sequence group is implementedaccording to different occupation modes of time-frequency resources ofthe sequence supported in the system as well as the rules such as staticor dynamic allocation. The operations of generating the sequence groupand constituting the sequence in the sequence group described in theabove embodiment of the invention may be implemented for all the cellsin the system. At this time, the mode of generating the sequence groupand constituting the sequence in the sequence group may be referred toas a common grouping mode of the cell. However, because when a sequenceis to be selected for usage, the selection of the sequence group may beperformed according to the cell specific pseudo random mode, and therandom number sequence specific to the cell may hop in the differenttime slots where the CAZAC sequences are carried, so a certain shortsequence will not always appear together with a certain long sequence inthe neighboring cell. Thus, when viewed in a long period of time, thesignal interference between the cells is random, so that the strongsignal interference between two cells may be avoided.

The above embodiments are illustrated by taking it as an example thatthe sequence in the sequence group is the CAZAC sequence generated fromZadoff-Chu sequence. However, the sequence in the embodiment of theinvention may also be the CAZAC sequence generated through othersequence generating methods. For example, the CAZAC sequence may also begenerated with Generalized Chirplike Sequence (GCL sequence). The GCLsequence can be represented as follows:

c(n)=a(n)b(n mod m), n=0,1, . . . , N−1.

Where N=sm², s and m are both positive integers; {b(n)} is a“modulation” sequence, the m elements in this sequence are all complexnumbers with module of 1, such as DFT sequence, b_(i)(n)=W_(m) ^(in),i,n=0,1,. . . , m−1. {a(n)} is a special “carrier” sequence, which maybe a Zadoff-Chu sequence. Further, {b(n)} may also be Hadarmardsequence, i.e., {b(n)} is one row of Hadarmard matrix. An m-orderHadarmard matrix H_(m) is an m×m-order matrix. The elements of thematrix are constituted of 1 and −1, where the matrix Hm satisfies thefollowing formular: H_(m)H_(m) ^(T)=mI, where I is a unit matrix, and Trepresents a matrix transposition. When m=2^(n), and n is a positiveinteger, the Hadarmard sequence is as follows:

${{b_{i}(n)} = \left( {- 1} \right)^{\sum\limits_{l = 0}^{m \sim 1}\; {i_{l} \cdot n_{l}}}},i,{k = 0},1,\ldots \mspace{14mu},{m - 1}$

Where i₁,n₁ are the l-th bit of the binary representation of i, n havinga length of m bits, respectively.

In the case of the CAZAC sequence generated by using the GCL sequence,the specific implementing processes for generating the sequence groupand allocating the sequences to the cells are basically the same as theimplementing process described in the above embodiment, and will thusnot be illustrated in detail again.

Another point that should be particularly pointed out is that the CAZACsequence in the above embodiments may also be a sequence generated byperforming interception on a CAZAC sequence, or may be a sequencegenerated by combining a fragment of a CAZAC sequence with a CAZACsequence.

Embodiment IV

The above embodiments of the method may be implemented with acommunication system shown in FIG. 7, where the system includes asequence allocating unit 701, and a sequence processing apparatus 700which includes cell sequence determining unit 702, a time-frequencyresource sequence determining unit 703, a sequence generating unit 704,and a processing unit 705.

The sequence allocating unit 701is adapted to allocate a sequence groupcontaining a plurality of sequences to a cell, and determine thesequences in the sequence group according to the occupation modes oftime-frequency resources of the sequence supported in the system. Thesequence group, occupation modes of the time-frequency resources and soon, are as described in the above embodiments of the method.

The cell sequence determining unit 702 is adapted to determine theavailable sequence group, such as determine the available sequence groupaccording to the information of the cell or the identificationinformation of the sequence group. The cell sequence determining unit702 may employ a plurality of modes as described in the aboveembodiments of method to determine a sequence that needs to begenerated, which will not be illustrated again here.

The time-frequency resource sequence determining unit 703 is adapted todetermine the sequence that needs to be generated from the sequencegroup determined by the cell sequence determining unit 702 according tothe occupation mode of the time-frequency resources. The time-frequencyresource sequence determining unit 703 may employ a plurality of methodsfor determining the sequence that needs to be generated as described inthe above embodiments of method to determine a sequence that needs to begenerated, which will not be illustrated again here.

The sequence generating unit 704 is adapted to generate the sequencedetermined by the time-frequency resource sequence determining unit 703.

The processing unit 705 is adapted to transmit the sequence generated bythe sequence generating unit 704 on corresponding time-frequencyresources, or use the sequence generated by the sequence generating unit704 in the processing of the sequence received on the correspondingtime-frequency resources, such as in correlation calculation at thereceiver. The specific implementation is as described in the aboveembodiments of method.

The above system includes a wireless communication sequence allocatingapparatus, which includes a sequence allocating unit 701 adapted toallocate sequence group for the cell, and determine the sequences in thesequence group according to the modes of time-frequency resourcessupported in the system which are used to carry the sequences.

The above system further includes a sequence processing apparatus in thewireless communication system for determining and processing thesequence. As shown in FIG. 8, the sequence processing apparatus 700includes: the cell sequence determining unit 702, the time-frequencyresource sequence determining unit 703, the sequence generating unit 704and the processing unit 705.

Those skilled in the art can understand that all or part of the stepsfor implementing the method in the embodiment may be implemented byinstructing relevant hardware via a program, and the program may bestored in a computer readable storage medium. For example, when theprogram is run, the following steps may be included: generating asequence group including a plurality of sequences, where the sequencesin the sequence group are determined according to the occupation mode oftime-frequency resources of the sequence supported by the system; andallocating the sequence group to the cell. The storage medium may beROM/RAM, magnetic disc, optical disc, and so on.

The scope of protection of the present invention is defined by the scopeof protection of the claims. Various variations and amendments to thepresent invention made by those skilled in the art without departingfrom the spirit and scope of the present invention fall within the scopeof protection of the claims of the present invention.

1. A method for allocating sequences in a communication system,comprising: generating a sequence group comprising a plurality ofsequences, wherein the sequences in the sequence group are determinedaccording to occupation modes of time-frequency resources of thesequences supported in the system; wherein the sequences in the sequencegroup at least comprises one of the following: constant amplitude zeroauto-correlation, CAZAC, sequence, a fragment of CAZAC sequence, and thesequence obtained through combining a CAZAC sequence with a fragment ofa CAZAC sequence; wherein the CAZAC sequence is a Zadoff-Chu sequence;wherein when the occupation modes of time-frequency resources of thesequences at least comprise: different sequences occupying thetime-frequency resources having different bandwidths, the generating asequence group comprising a plurality of sequences comprises: taking twosequences occupying the time-frequency resources having differentbandwidths as the sequences in the sequence group; wherein indexes r_(i)of the two sequences comply with r_(i)=b_(i)·k+δ_(i), i=1,2; wherein thesame k indicates the same sequence group, b_(i), δ_(i) are determined bythe time-frequency resources having different bandwidths occupied by auser, and i=1, 2 differentiates different time-frequency resources; andallocating the sequence group to a cell.
 2. The method according toclaim 1, wherein when the occupation modes of time-frequency resourcesof the sequence comprise: different sequences occupying thetime-frequency resources having different sampling intervals s₁, s₂ ,the generating a sequence group comprising a plurality of sequencesspecifically comprises: performing sampling having intervals of s₁ ands₂ on the sequence corresponding to the time-frequency resources thatare sampled, and taking two sequences a_((si)mod M), i=0,1, . . . ,M−1,s=s₁,s₂ obtained through the sampling as the sequences in the sequencegroup; or when the occupation modes of time-frequency resources of thesequence comprise three occupation modes, and the three occupation modesof time-frequency resources respectively correspond to a first sequencea, a second sequence b and a third sequence c, the length of the thirdsequence c is larger than that of the first sequence a and that of thesecond sequence b respectively, and the third sequence c is a product ofthe first sequence a and the second sequence b, the generating asequence group comprising a plurality of sequences specificallycomprises: taking the third sequence c and one of the first sequence aand the second sequence b as sequences in the sequence group.
 3. Themethod according to claim 1, wherein when the occupation modes oftime-frequency resources of the sequence comprise: two sequences,obtained through performing samplings having different intervals,occupying the time-frequency resources having the same bandwidth, andwhen indexes of the two sequences are directly proportional to thesquare of the corresponding sampling intervals, the generating asequence group comprising a plurality of sequences specificallycomprises: taking the two sequences as the sequences in the sequencegroup; or when occupation modes of time-frequency resources of thesequence comprise two or more occupation modes, the generating asequence group comprising a plurality of sequences specificallycomprises: taking two sequences corresponding to two differentoccupation modes in the sequence group, wherein indexes r_(i) and r_(j)corresponding to the two different occupation modes satisfy the relation${\frac{r_{i}/g_{i}^{2}}{r_{j}/g_{j}^{2}} = \frac{b_{i}}{b_{j}}},$wherein g_(i) and g_(j) indicates that a sub-carrier is occupied inevery g_(i) sub-carriers and g_(j) sub-carriers respectively in the twodifferent occupation modes in the frequency domain; wherein b_(i)/b_(j)indicates a value determined by the ratio of the occupied bandwidths inthe two different occupation modes.
 4. The method according to claim 1,wherein the generating a sequence group comprising a plurality ofsequences further comprises: determining b₁, b₂ according to an equationb₁·N₂−b₂·N₁=1, where N₁, N₂ represents lengths of the differentsequences respectively.
 5. The method according to claim 1, wherein whenthe occupation modes of time-frequency resources of the sequences areclassified into several classes, the generating a sequence groupcomprising a plurality of sequences further comprises: constituting acorresponding sequence group for the occupation modes of time-frequencyresources of the sequence in each class.
 6. The method according toclaim 1, wherein the determining the sequences in the sequence groupaccording to an occupation mode of time-frequency resources of thesequence supported in the system specifically comprises: constituting,by the sequences having relatively high correlation between each other,the sequence group when the corresponding time-frequency resources areoccupied.
 7. The method according to claim 1, wherein the allocating thesequence group to a cell specifically comprises: allocating the sequencegroup to the cell in a pseudo random mode.
 8. The method according toclaim 7, wherein the allocating the sequence group to the cell in apseudo random mode specifically comprises: allocating the sequence groupto the cell in the pseudo random mode specific to the cell, or in thepseudo random mode specific to a cell group.
 9. A method for sequenceprocessing in a communication system, comprising: determininginformation of a sequence group allocated to a cell; determining thesequence generation information from the information of the sequencegroup according to the occupation mode of time-frequency resources ofthe sequence; generating the sequence according to the sequencegeneration information; and performing sequence processing on thesequence generated; wherein the sequences in the sequence group at leastcomprises one of the following: constant amplitude zeroauto-correlation, CAZAC, sequence, a fragment of CAZAC sequence, and thesequence obtained through combining a CAZAC sequence with a fragment ofa CAZAC sequence; wherein the CAZAC sequence is a Zadoff-Chu sequence;wherein when the occupation modes of time-frequency resources of thesequences at least comprise: different sequences occupying thetime-frequency resources having different bandwidths, two sequencesoccupying the time-frequency resources having different bandwidths aretaken as the sequences in the sequence group; wherein indexes r_(i) ofthe two sequences comply with r_(i)=b_(i)·k+δ, i=1,2; wherein the same kindicates the same sequence group, b_(i), δ_(i) are determined by thetime-frequency resources having different bandwidths occupied by a user,and i=1, 2 differentiates different time-frequency resources.
 10. Themethod according to claim 9, wherein the determining information of asequence group allocated to a cell specifically comprises : determiningthe information of the sequence group allocated to the cell according toidentification information of the cell and/or identification informationof the sequence group.
 11. The method according to claim 9, wherein whenthe occupation modes of time-frequency resources of the sequencecomprises: the different sequences occupying the time-frequencyresources having different sampling intervals, two sequencesa_((si)mod M), i=0,1, . . . ,M−1, s=s₁, s₂ , obtained through performingsampling having intervals of s₁ and s₂ on the sequence corresponding tothe time-frequency resources that are sampled, are taken as thesequences in the sequence group; or when the occupation modes oftime-frequency resources of the sequence comprise three occupationmodes, and the three occupation modes of time-frequency resourcesrespectively correspond to a first sequence a, a second sequence b and athird sequence c, the length of the third sequence c is larger than thatof the first sequence a and that of the second sequence b respectively,and the third sequence c is a product of the first sequence a and thesecond sequence b, the third sequence c and one of the first sequence aand the second sequence b are taken as the sequences in the sequencegroup.
 12. The method according to claim 9, wherein b₁, b₂ aredetermined according to an equation b₁·N₂·b₂·N₁=1, where N₁, N₂represents lengths of the different sequences respectively.
 13. Themethod according to claim 9, wherein when the occupation mode oftime-frequency resources of the sequence comprises: two sequences,obtained through performing samplings having different intervals,occupying the time-frequency resources having the same bandwidth, andwhen indexes of the two sequences are directly proportional to thesquare of the corresponding sampling intervals, the two sequences aretaken as the sequences in the sequence group; or when occupation modesof time-frequency resources of the sequence comprise two or moreoccupation modes, two sequences corresponding to two differentoccupation modes are taken as sequences in the sequence group, whereinindexes r_(i) and r_(j) corresponding to the two different occupationmodes satisfy the relation${\frac{r_{i}/g_{i}^{2}}{r_{j}/g_{j}^{2}} = \frac{b_{i}}{b_{j}}},$wherein g_(i) and g_(j) indicates that a sub-carrier is occupied inevery g_(i) sub-carriers and g_(j) sub-carriers respectively in the twodifferent occupation modes in the frequency domain; wherein b_(i)/b_(j)indicates a value determined by the ratio of the occupied bandwidths inthe two different occupation modes.
 14. A wireless communicationapparatus for signal processing, comprising: a cell sequence determiningunit, configured to determine information of sequence group allocated toa cell; a time-frequency resource sequence determining unit, configuredto determine the sequence generation information from the information ofsequence group according to the occupation mode of time-frequencyresources of the sequence; a sequence generating unit, configured togenerate the sequence according to the sequence generation information;and a processing unit, configured to perform sequence processing on thesequence generated; wherein the sequences in the sequence group at leastcomprises one of the following: constant amplitude zeroauto-correlation, CAZAC, sequence, a fragment of CAZAC sequence, and thesequence obtained through combining a CAZAC sequence with a fragment ofa CAZAC sequence; wherein the CAZAC sequence is a Zadoff-Chu sequence;wherein when the occupation modes of time-frequency resources of thesequences at least comprise: different sequences occupying thetime-frequency resources having different bandwidths, two sequencesoccupying the time-frequency resources having different bandwidths aretaken as the sequences in the sequence group; wherein indexes r_(i) ofthe two sequences comply with r_(i)=b_(i)·k+δ_(i), i=1,2; wherein thesame k indicates the same sequence group, b_(i), δ_(i) are determined bythe time-frequency resources having different bandwidths occupied by auser, and i=1, 2 differentiates different time-frequency resources. 15.The apparatus according to claim 14, wherein b₁, b₂ are determinedaccording to an equation b₁·N₂−b₂·N₁=1, where N₁, N₂ represents lengthsof the different sequences respectively.
 16. The apparatus according toclaim 14, wherein, when the occupation modes of time-frequency resourcesof the sequence comprises: the different sequences occupying thetime-frequency resources having different sampling intervals, twosequences a_((si)mod M), i=0,1, . . . , M−1, s=s₁,s₂ , obtained throughperforming sampling having intervals of s₁ and s₂ on the sequencecorresponding to the time-frequency resources that are sampled, aretaken as the sequences in the sequence group; or when the occupationmodes of time-frequency resources of the sequence comprise threeoccupation modes, and the three occupation modes of time-frequencyresources respectively correspond to a first sequence a, a secondsequence b and a third sequence c, the length of the third sequence c islarger than that of the first sequence a and that of the second sequenceb respectively, and the third sequence c is a product of the firstsequence a and the second sequence b, the third sequence c and one ofthe first sequence a and the second sequence b are taken as thesequences in the sequence group.
 17. The apparatus according to claim14, wherein, when the occupation mode of time-frequency resources of thesequence comprises: two sequences, obtained through performing samplingshaving different intervals, occupying the time-frequency resourceshaving the same bandwidth, and when indexes of the two sequences aredirectly proportional to the square of the corresponding samplingintervals, the two sequences are taken as the sequences in the sequencegroup; or when occupation modes of time-frequency resources of thesequence comprise two or more occupation modes, two sequencescorresponding to two different occupation modes are taken as sequencesin the sequence group, wherein indexes r_(i) and r_(j) corresponding tothe two different occupation modes satisfy the relation${\frac{r_{i}/g_{i}^{2}}{r_{j}/g_{j}^{2}} = \frac{b_{i}}{b_{j}}},$wherein g_(i) and g_(j) indicates that a sub-carrier is occupied inevery g_(i) sub-carriers and g_(j) sub-carriers respectively in the twodifferent occupation modes in the frequency domain; wherein b_(i)/b_(j)indicates a value determined by the ratio of the occupied bandwidths inthe two different occupation modes.
 18. The apparatus according to claim14, wherein the cell sequence determining unit comprises: a moduleconfigured to determine the information of sequence group allocated tothe cell according to identification information of the cell and/oridentification information of the sequence group.
 19. The apparatusaccording to claim 14, wherein the time-frequency resource sequencedetermining unit comprises: a module configured to determine the indexof the sequence that needs to be generated according to a moduleoperation (X mod n), wherein X is the index of the sequence group, n isthe number of candidate sequences corresponding to the occupation modeof time-frequency resources of the sequence.
 20. The apparatus accordingto claim 14, wherein the apparatus is a user terminal or a networkentity.